Method of preparing screens for color photography.



Patented June 13, 19.11.

L. DUGOS DU HAURON L R. DE BERGEGOL. METHOD .OP PRBPARINGSOREBNsJ-"OROOLOR PHOTOGRAPHY.

Y APPLIGATIGN FILED JUNE 22, 1910. 95,4959

my mum WTIVESSES:

ravir oserais,

LOUIS DUCOS DU HARON AND RYMOND DE BERCEGOL, 0F JON'VILE-LE-PGNT,FRANCE.

- METHOD OF PREPABJING SCREENS EUR COLOR PHTQGRAEHY.

Original application fled January dents of Joinvillede-lont, Seine,Republic of France, have invented. new and linproved Method of Preparingncreens tor Color Photography, of which the following isea full, clear,and exact. description, this being a division ot the application tiled.by

us on January 2, i90?, Serial ,NoA itiea, for the manufacture of screensttor use in coloil 'ihotography.

Our invention relates to the .manufacture l5 of polychromatic screensfor usein color photography, under such conditions that the pictures orportions thereof may be multiplied.

,Ve seek to cover a transparei'xt or trans lucent surface, of glass,Celluloid, paper or the like, 'with a very lz rge num ber ot ingly smallrectangular figures, such as bands, rectangles, losaenge-shaped ligures,etc., having 'three distinct colors placed 25. closely together' withoutleaving any interval, and cach ot' these colors covering theoreticallyone-third of the surface. By doing this in a skilful manner, the processmay be carried out rapidly, economically and in every manner suitabiefor industrial conditions.

Two things are essential in carrying out our process, to wit: First, theautomatic placing or positioning ot the colors relatively to each other,by taking advantage ot the fact that colors dissolved in liquids ofdiderentcharacterdo not readily mix-that is to say, colors mixed withgreasy substances and colors dissolved in water -or in alcohol,

do' not mix easily; second, the application of these colors thustreated, to'parallel lines by means'ot' a ruling machine.

Several forms of the invention are herein illustrated and described inorder to render the process easily understood.

figures.

Figure 1 shows on an enlarged scale a portion of the screens obtained bythe process;

Figs. 2, 3 and It, show variationS FgliS. a

Specification of Letters Patent.

i?, i907, i tial No. 35G,33l.

1911:, Serial Patented June i3, Miti.

1Qivded and this application filed June 22,

fide View of a machineifor tracing the lines; l `.ig. (i is a plan view;Fig. 7 is an end view; and Tig. S is a section on the line ofthe cuttingtool.

"vile select a hard plane surface, preferably one 'or copper, Zinc oriithographic stone, A upon this surface lines, are drawn by et amachine, these lines being paral with' ach other and separated byinterl` This being done, the surface is partly relic-ii' and partly inintaglio. r "he parts relierp are next coated, or the intaglio poriciwith a greasy coloring materiale-for instance, green printing ink. Bymeans or" pressure the series of lines is now reproduced upon a sheet ofgelatin, or upon some other appropriate surface adapted to receive animpression; This is now dried. and after drying a formed. This color,tor instance, may be orange, and is so arranged that the lines crossthose iirst made. The bare intervals are next colored by applying to thewhole surface of the sheet a third color, blue violet, dissolved inwater, and to which the greasy colors are impermeable. rEhe screen thusmade possesses, as shown upon a large scale in l, large number ofcomparatively small ligures or designs, which may have the form ofsquares, rectangles, or losenges, accordingly the ot lines areperpendicular or oblique.

At v is shown the green color, at 7 the orange color, and at b the bluecolor. At the crossings of the various lines appear small patches oft'black or dark color nwhich present a very slight disadvantage, to wit:that of slightlydarkening the entire screen. The black or ydark lelementn may be avoided, however, by operating as follows: Upon a surface, suchas gelatin capable ot dissolving water color, we I lines, substantiallyas heretofore described, by means of a greasy ink of blue violet color,and then a yellow water color is applied over the entire surface. Thematerial thus applied does not adhere to the greasy lines and only fillsthe 4intaglio portions comprised between these lines. second series oflines is then drawn by means of a greasy ink of light blue color, cfrebeing taken tlo cross the lines just mentioned. The `light s (that is,the holes or grooves) are covW tracing of another color lmay be" seriesfirst draw a series of l sheet of sure, the unevenness of the glass.

makin the Gelatin 55 1 g e blue lines in' being superposed upon theyellow lines will produce green colors, and in being superposed upon theblue violet color will have little or no effect beyond slightlyincreasing the intensity of this color. These three operations produceon the gelatin surface blue violet lines and green rectangles, resultingfrom the superposition of the yellow lines on the light blue lines; andsince the lines and the squares are produced by inks having greasysolvents, these lines are not'attacked by the other colorwhose solventis water.` Finally, over the'ientire surface is applied a layer of redwater color which in mixingv with t-he yellow gives the orange redcolor.

Our process may be used in connection With glass surfaces as follows:Upon a glass we spread gelatin holding in suspension very linegrains,.such as those of starch. The she'et is then dried, the resultbeing a slightly grainy surface holding the greasy ink and avoidingblurring, as well as enabling us to obtain, under the press, seriesof'lines having remarkable clearness. To avoid breaking the glass andalso to ren'- der the prints homogeneous, the plate produced by theruling machine 'must be absolutely smooth, or better still, made up of asoft material, such as ebonite,icelluloid, or very thin metal, placedona sheet of indiarubber or other lieXible material, so as to eX- a-ctlycompensate, when submitted to pres- The two colors in greasy inks areapplied as above'described and the gelatin is caused to absorb the watercolo-r which now lls the hollows and completes the trichromatic screen.If it happens thatthe third. color is blue violet, there can still beadded to the gelatin, before it spreads over the 'transparent support,starch, which in this case must be dissolved. The last operationconsists in causing to act in the greasy hollows upon the intaglioportions, causes the starch color.

The present process can also be carried out as follows: l. On asubstance permeable to water a first set of greasy lines which may tobecome of a blue violet be colorless, is drawn; 2. Over the whole colorcontaining tannin,

surface an aqueous alum, or any other substance susceptible ofimpermeable to color soutions similar to thatfirst applied, is applied;3. By means of a dissolvent, such as turpentine or mineral essence,etc., the greasy lines are destroyed in order that only the aqueouscolor lines may re1nain. 4. A second set of greasy lines crossing thepreceding lines, and which may be colorless, as the rst ones, is drawn;5. A second water color, likewise containing tannin, alun etc., isapplied over the whole surface; 6". As previoisly done, {said second setof greasy a solution of iodin which lines is destroyed; 7. Finally, thethird* water color is applied over the whole surface.

If there be mixed with the water -color a suitable proportion ofmaterial having the property of tanning gelatin and filling 'the poresthereof-in other words, if we add to the water color alum, tannin,alcohol, aldehyde, or the like-the space occupied by this color will bethereby rendered impermeable. A second aqueous color is now applied bythe saine means, and lafter drying, the third color, which is likewise awater color andv though spread over thewhole surface, will adhere onlyto the intaglio portions left.

Instead of obtaining the lines by transfer, they'may be drawn directlyupon thel 'Y case the procedure is as follows: A sheet of glass orCelluloid is first covered with a material which is permeable to waterand which is colored, for example, red. Then by means of a plane `orcircular ruling machine we draw small parallel screen. In this grooveswhich are "separated 'by intervals approximating their width. The sheetthus prepared is dipped for a few seconds into a water color green, forexamplefwhich iinpregnates the gelatin 'throughout wherever it has beenexposed, leaving unaffected the parts `covered with varnish and merelydyeingsupercially the layer of gelatin.

e surface is nowclean. lt constitutes, in elfect, a screen composed ofgreen and red orange bands arranged side-by 'siderelatively to eachother and capable of produce ing, by the two-color process, beautifullycolored photographs.

The third color is distributed as follows: There is' spread over asurface provided with two series of bands or lines, a second varnishwhich is impermeableto water, is colorless, and is designed to servesolely as" a protector; we then hollow out fresh tracks which are alittle deeper than those above referred to, in such a manner pasitoexpose the lower layer "of gelatin which the rst icc lio

bath did not have time to reach. These f tracks intersect the iirsteither -perpendi'cularly or obliquely and should be separated b. fspaces equal to twice their own width. The sheet vvisthen dipped for afew seconds into a blue-violet watercolor bathV and a three-color screenis produced. c It has aneXtremely large number of small green andred-orange rectangles, o, e, respectively, intersected by blue-violetlines as shownin Fig. 2 0f ,the accompanying drawings These smallfigures will be lozenge-shaped if the second series of bands or trackshas been drawn obliquely, as shown in Fig. 3 of the drawings. The colorsmay mentioned ones obviously he.ar ranged in any desired order.

We may also .take a transparent sheet covered withA a thick layer ofgelatin which is supericially colore reen for example. on

which is spread a varnish impermeable Water. 1. having; drawn the lirstseries of bands or tracks, the sheetdipg'ied into av second water-colorhath as Jor instance, rederange-color, ren a colorless protectivevarnish is spread thereon, the second deeper series of bands or tracksis drawn and iinally the sheet is dipped into ,hird watercolor bat-h,as, for instance, blue-violet. Celluloid which is sfiperlicially coloredgreen, 'for example, may also be employee; this is corered withcol:nl'ess gelatin and the series o' bands or tracks drawn suliicientlydeep' for them to ezqpose the colorless Celluloid. rl`he sheet is thencolored with a pigment solved in acetone, amyl acetate or any otherliquid which will bite into or penetrate the cellnloid. There .is thenspread over the whole surface a sec nd layer of `gelatin, then thesecond deeper series of bands or tracks is drawn, and finally `tht-ireis spread over the whole surface a. third color having; a base ofacetone or amyl acetate.

The gelatin having protected the parts olf the surface not acted upon bythe chisel or tool` of' the ruling machine, and alter having freed thecelluloid from tne gelatin, there will he produced a screen which iscapable of resisting water and a large number oi' other liquids.

ln nsinf:Y celluloid the procedure is as follows: The sheet of celluloidis covered with a thin layer oit gelatin which is colored by means` of awater color, then the first series of bands or tracks is drawn throughthe gelatin; the sheet is colored with a second color having amylacetate or acetone for its base, which only acl'spon the exposed partsof the Celluloid, the whole is then covered with a second layer ofcolorless `gelatin; the second series of liands or tracks which aredeeper than the former onesl drawn and a third color of the same natureas the second is spread over the sheet.

In all the above cas the vfirst series oi bands or tracks can be drawnin such amanner that the. interval which sol'mrates llleni shall beequal to twice their width7 :is shown in Fig'. 4 oi' the dra wings.Then, after soaking and varnishing', sil'nilar bands or tracks are drawnexlenrlixre` nearly lo the middle oli the space which is afterwardsoaked in the third color.' ln this i'nanner, the screen is formedsolely by bandsl which are parallel lo each other, but this l'n'ocesshas the disadvantage of only overcoming` part of the dill]- cultics oipvregistration, while the method in which. the lines4 cross ovel'eonn-,s`lheln entirely. Thus, the second series ol' bands or tracks can behollowcd to the saine extent as the lirst; in this ease, two colors aresuperposcd and 'lorin at the point at which the series of linesI crosseach other as hereinloefore specified and as shown in Fig. l- .small mayhe used in which these machines a plurality o fixing we will A :treswhich are blacl or have a dark e el 1 in most cases, as above seciliedthe gelatin Tn be replaced by collodion or by any other material whichmay be easilv spread in a thin layer and colors having water, hases."

i For drawing lines, the ruling machines ehisels are `We'ierably on lsor gravers arranged so as to torni a number of lines at a time. Also,.inorder to produce filinlike screens, we. can use a cir-cular rnlingimachine similar to that shown by .va\y\o't` eX- ample in Figs. 5, G, 7 and8.

employed, and by mountiniY inls machine consist-s oi a movable cylinderl around which the sheet is rolled, and of a chisel or cutting tool i2which'is lied along by a leading' screw 3, and toothed wheels Ll and 5,of which the wheel 5 is attached to the shaft olil the cylinder' l. lnorder that the eye may not he able to distinguish separately thesinallcolored divisions, their dimensions should be made as small aspossible, and thus a surface will be obtained which will appearhomogeneous and Whitish by transn'iittent light.

ln order to allow the use of rotary pressure, the series-of lines can bedrawn on cylinders.

` ln use, the screen inoduced by one of the methods described above, andprotected by an Aimpermeable varnish, is covered -With an emulsion whichis sensitive to colors, and

vis placed in the plate or liln'i-carrieror frame .oll any suitablephotographic apparatus,'the

emulsion being turned toward the inner face ot the said -carrier or'l'ranxe in such a manner that the rays of light pass through the screenbefore reaching` the said emulsion. A view will be laken in the ordinarymanner and developed, then the negative so obtained will be convertedinto a positive and after have a photograph having all the naturalcolors; at the saine time., we can employ the following' process when itappears to be more advantageous by reason of its permitting theproduction of a large number of prints.

lnstead oi spreadingthe' emulsion on the screen itself, there is placedin the carrier or traine, in the ordinary manner, a sensitized plaie towhich the screen is applied, by putting; the colored surface of thelatter against the emulsion on the plate. The' View .is laken, then theplate is developed after havino` been separated from the screen. Theselectively acted nponY negative thus produced, when lixed, will enablean indenite number ot' black positives to be obtained which, whensuitably placed against similar screens will innnediately exhibit bytranscapahlc oi absorbing uted vover the Whole surface of the screen,

mitted light all the colorations of the model. Theoretically thisadaptation or tting of the screen to the positive, should be made insuch a manner that each of the small colored figures should 4coincidewith the point of the image which it has selected, but since thesethousands of figures or devices are similar to each other, are of equaldimensions and are synnnetrically distribb vreason of the regularity ofthe Work done by the ruling machine, the registration may easily takeplace with an infinity of positions.

The transparent support of the improved screens serving for theselection may be colored slightly yellow so as to moderate the activityof the blue-violet rays. The successive crossing of the two seriesof'lines thus assists the complications of registration in themanufacture of the screens. lNIore- .o\er, the successive soakings eachtime exactly lilling up the spaces producechit follows that all thesmall color-compartments are automatically juxtaposed without any spacebeing left between them, a condition which is especially advantageous inthe production of phototypes in which the selective effect is producedby light-filtration. The perfect regularity of the4 screens enables themto be applied to any positive produced by a similar screen, andconsequently to enable the prints to be multiplied` indelinitely.

Having thus described our invention, We vclaim as new and fiesire tosecure by Let ters Patent:

l. The method herein described of making screens with polyclnomaticdivisions, which consists in first impressing upon a transparcut supportdefinite spaced figures, next coloring the intervals not covered by thefigures by means of a color solution that will enter thesupport in theparts unprotected'by the.A

printing substance but will not 'affect this substance, next renderingimpermeable to lcolor solutions the parts of the support alreadycolored, then destroying the printing substance impression and finallycoloring the permeable intervals by means of a color that will enter thesupport.

' 2. The method herein described of making I adestroying the fatty linesby means of a suitable solvent, then impressing a second group of fattylines crossing the irst group, then applying a second color capable ofentering the permeable parts of the support unprotected by the fattyprinting substance, said second color being non-miseible with saidsubstance, then rendering impermeable to color solutions the new coloredparts of the support, then destroying the second` group of fatty linesby dissolving the same, and finally applying a third color capable ofcfr entering the permeable unprotected parts of the support. v

In testimony whereof We have signed our names to this specification inthe presence ofvr two subscribing witnesses.

Witnesses f DEAN B. Mason, R. Ennuor.V

